Tooth brush



Jan. 9, 1940. G. L cAsTo 2,186,005

TOOTH BRUSH Filed April 25, 1939 2 Sheets-Sheet l Gttornegs G. L. CASTO TOOTH BRUSH 7 Jan. 9, 1940.

2 sheets-sheet? Filed April 25, 1939 B azm 2. M

(Ittorneg' Patented Jan. 9, 1940 0 PATE Tjorrlct mm BRUSHU? I n n 3 Glenn L Casto, Spencer, W.-Ya. 1 I Application April 25, 1939', Serial No. 270,005

5 Claims. (01, 15-161) I The present invention relates to'improvements in tooth brushes and is a'continuation in part of my application filed No. 187,681. v

An object of the invention is to provide-an improved tooth brush involving a novel formation of the working point of the brush whereby an improved action is had upon the teeth in that more adaptationof the working point upon the non-self-cleansing areas of the teeth is secured. for instance upon such areas-as the gingival third, gingival crevice, dental embrasure and incisoral spaces. I

Another object of the invention resides in providing an'improved' tooth brush in which by the act of forming the working point conforming to January 29,1938, Serial the convexity of the tooth certain bristle heads or free ends are converted into combined chisel points and bevel surfaces, with the chisel points so arranged with respect to the handle and head of the brush and with respect to the bevel surfaces that such chisel edges will be a potent factor in the normal operation of the brush to remove food deposits from the teeth andfrom spaces betweenthe teeth, and whereby the bevel surfaces but on the other hand being such as to be manip ulated in presentlyaccepted modes of operation; and-the invention-further contemplates that the advantages of the new construction be had without sacrifice of increased cost, v

With the foregoing and other objects in'view,

the invention will be more'fully described herein-- after, and will be more particularly pointed out in the claims appended hereto.

In the drawings, "wherein like symbols referto like or corresponding parts throughout the several views,

Figure 1 is agside elevation of an improved tooth brush constructed in accordance with the present invention. l

Figure 2 is a plan view of the same.

Figure 3 is an end elevation, of the improved brush, taken on an enlarged scale.

- brush.

showing the improved brush, with ahandle partly broken away in' a difierent-application of the characteristics of skilled '12,, and

cate the transverse axis of the brush head.

Figure 4 is gag-fragmentary side view ofoneof' the-chisel'bristles employed at one side of the f-Figure 5 is a similar view showing the form of 'ch-iselbristle employed at'the other side of the brush. p Figure 6 is -a fragmentary perspective view showing,-on an enlarged scale, a unit of the bristle and'tuft assembly. v

Figure lisp asi'milar view taken at substantially right angles to Figure 6. v Figure 8 is a schematic view showing geometrically the lay, form and development of the worke ing point ofthe improved brush. Figure 9 is a fragmentary plan view of a slight- 1y modified form of brushin which theunits are ovals or-ellipses rather than circles as shown in Figure2.- m

Figure 10 is a fragmentary perspective-view of a denture showing an application of the improvedbrush-in one position. 1- I 1 Figure 11 be similar view with the brush in the'subsequent horizontal position compared with r Figure 10;

same to the teeth. I I

'Figure 13 is a fragmentary outer perspectiveview of a denture with the improved brush shown as'being applied in, the manner similar-to Figure Figure 14' is'a vertical fragmentary. section through the mouth showingthe gum and a tooth- With' full and'dotted positions of chisel and long bristles: 5

Referring more-particularly to the drawings 15 designates the'handle of a tooth brush carrying the-head backing plate l6 and the brush head composed of the bristles, which, according to the invention,'are assembled and constructed to form a novel working point for the. brush.

AB represent-thelongitudinal axis of the brush head as seen in Figure 2 and 0-D indi- As shown in Figure3 the bristles of the brush are grouped into-tufts. As seen in Figure Zthe tufts are arranged in circles, four such'circles being shown; although a greater or'lesser number of such circular unitsmay be employed. v

"In Figures 6 and '7 one such circular unit is 50 shown comprising eight tufts numbered separate- I lyll to 24. inclusive. In the single embodiment of this invention, as shown in the drawings,;eight such tufts are ShOWIlr' This is found to-be a very satisfactory arrangement; although greater or -1 v lesser numbers of tufts may be employed. Also a commercially practicable form of the invention involves thirty-six bristles to each tuft but this number of course may be varied as desired.

The working point of the brush, which is constituted by the free ends of the bristles of the various tufts of all the units, is formed on a compound curve which consists of the following three elements. The first element is the circular grouping of the tufts l'l-24 as above described; the second curvature involves that shown in Figure l in which the working point of the brush is out along its longitudinal axis with inverted arches 25; and the third member of the compound curve is formed by the indentations 26 shown in Figure 2 as being made by the arcuate portions of the circles of the tufts as the same-- come together at the tangent points of the various circles. v

In addition to this compound curve,-composed of these three separate components, the working point of the brush has superimposed upon it a lateral trim formed by trimming the free ends of the bristles in diagonal planes 2? and 29, which I thereof, and produce, as shown in Figure 3, long oi the brush head and lateral, shorter bristles bristles down the center of the longitudinal axis to both side soi these long central bristles. In this Figure 3 just above these diagonal planes 2'! and 28 the cutting tool is passed inan arcuate movement up toward the long central bristles 35 so that at the intermediate sides of the long central bristles 35, the lateral chisel "bristles are cut on a progressively less sharp angle from the sides toward the longitudinal'center of the brush whereby to graduate the chisel action from zero at the longitudinal center line of the brush down to the outer-portions of the lateraledges of the brush. This formation will give greater protection to the gums and to the self-cleansing portions of theteeth'as the rotary action of the brush in cleaning takes place over these surfaces.

The lateral bristles partake of the lateral trim. In Figure 4 one such bristle 29 is shown as being out along the diagonal plane 27 of Figure 3.

This bristle 29 is thus cut with a bevel edge 30 terminating in a chisel point 3|. The chisel point is at the high or inner edge of the bristle 29. In Figure a lateral bristle 32 is shown as appears at the opposite side of the brush, this bristle 32 having at its upper free portion a bevel edge 33 terminating in a sharp point 34v forming a chisel edge. In Figure 3 the long central bristles are indicated at 35, the same having arcuate outer ends or tips 35.

In Figure 14 one of the long bristles 35 with its arcuate tip 36 is shown in conjunction with one of the shorter chisel bristles 32. The relation of these bristles will be described more fully hereinafter.

Figure 9 shows an oval, rather than a circular grouping of the tufts of bristles, the long axis of the ovalor ellipse being. transversely of the brush head in order to accommodate high or deep teeth. The word tubular-in the claims is intended to cover the circular grouping of the tufts as shown in Figure 2 or the oval or elliptical arrangement, as shown in Figure 9, or any other tubular form or arrangement of the tufts.

In Figure 8 there is indicated geometrically how the curvature of one unit of the working point of the brush is plotted geometrically. In this figure 37 indicates a cylinder of hollow form, it being intended that the tufts be distributed around in this cylindrical arrangement. The upper end of the cylinder 3'! representing the working point of the unit is cut down upon the arcuate line 38 to produce the high points 39 and the low points 40. Then the upper part of the cylinder forming the low sides 49 is cut on the diagonal lateral planes so that the upper edge of the cylinder no longer lies horizontal but diagonal and due to the curvature of this edge of the cylinder and the high and low points 39 and 49, the diagonal trim will be deepest at the central part 4| and will decrease in direct proportion upwardly towards the two high points 39, thus giving to the diagonal trim, when viewed from the position of Figure 8, a substantially crescent appearance,

the lateral cleavage or trim is not carried up uponv the high ends 39. Therefore the high ends 39 which extend along the longitudinal axis of the brush form the zone where the long bristles 35 are placed having the arcuate tips 36. The low points 49 are presented to the sides of the brush and the short chisel bristles 29 and 32 lie in these diagonal plane areas with their bevel edges and sharp points constituting chisels cut in relatively opposite directions at opposite sides of the brush-and at opposite sides of the long bristles 35.

In the intradental or rotary brushing, the

brush will have a chisel action. The lateral bristles which have the chisel points leading in the direction of brushing will act to remove food debris with a much less vigorous brushing action than nowv required with the ordinary form of tooth brush. At the same time the bevel edges 39 or 33 on the upstroke will lead the chisel points 3! or 34 and consequentlywill prevent these chisel bristles from tearing the gum. In other words on the upstroke of the brush the bevel edges will be presented and on the down stroke the sharp chisel edges will be presented to the teeth. Due to the inclination on which the bevel edges 30 and 33 are out, these bevel edges will be greater in area than the horizontal cross sectional area of the bristles 29 and 32 and therefore the protective bevel action is in creased and made substantially by this formation of the free ends of the lateral bristles.

The circular, oval or tubular grouping of the tufts of bristlesis for the purpose of conforming substantially to the. vertical curvature of the gingival third areas of the teeth. The inverted arches 25 at the working point of the brush enable such working point to fit around the horizontal curvatures of the gingival third areasand also around the convex front portions of the teeth. The crescent shaped areas produced by the lateral trim fit at the same time the gingival third areas when the brush istilted, as in the manner indicated in Figure 12 and 13.

In other words during. the tilting of the brush. as'it is used in 'diggingor excavating action in intradental brushing, the crescent shaped area of the working point of the brush is brought against the gingival third areas of the teeth. This cre'scent shaped area yields more adaptation; to the gingival third and thereby removes the food debris with the utmost efficiency. The'greateradaptation means substantially more contact between working point of the brush and the treated tooth area. I

Where single lines of bristles, whether arranged circularly or not, are used the chance'is very small of touching all parts of the gingival-third area because a part of such area is next the gum and in a particularly difficult locality because the shape of the gingival third is that of a twisted or torsional arced area. The diagonal section of the trim in combination with the various other curvatures imposed on the working point of the brush yield the crescent shape which lies throughout in contact with the entire gingival third area when the brushis turned in the manner of application shown in Figures 12 and 13. I

The diagonal section or lateral trim thus pro-' duces three results; first it provides a substantially crescent-shaped area at the working point of the bristles to lie throughout in contact simultaneously with the entire area of the gingival third; secondly, it imparts a chisel form to the free ends of the lateral bristles; and third it creates a bevel against the gum instead of a sharp corner.

When the brush is moved back and forth hori-.. zontally, as shown in Figures 10 and 11, where the bristles are at substantially right angles or horizontal to the tooth surfaces, the high points of the bristles which are the long tufts ride up on the dental embrasures-and lift the short lateral bristles off the free margin of the gum and off the dental propillae, which is the part of the gum projecting down between the teeth. Thehighest or longest bristles (namely those in the longitudinal center of the brush) are not trimmedand do not have chisel points and the convex tips of these long central bristles are the only ones that touch the dental propillae and the gum tissue. No others can touch these parts unless the brush is turned on the side, and in that event the bevel faces of the lateral short bristles on that side of the brush protect the gum tissue and propillae The heads of the long bristles in the center. of the brush are rounded so as to ride smoothlyjover the gum surfaces and prevent the points of the shorter chisel edge bristles from digging into the.

gum surface.

The tubular arrangement of the tufts produces also a hollow center to avoid bringing pressureto v bear on the convex surfaces of the teeth because the pressure is desired at the margin of the circle which corresponds to the gingival third, dental embrasure and interproximal space. It is not desirable to have any pressurein the center of the circle which is the immune area of the teeth cleansed by the tongue, lip and cheek. Bristles in the central portion of the tubular groups would only produce abrasion and make absolute cleansing of the brush difficult. Only one row of tufts in each circle or tube simplifies cleaning of the brush. Also these central areas indicated at 43 in Figure 2 form repositories to hold dentrifice, which is automatically fed out to the tooth surface as such dentifrice is used. These central areas 43 therefore form natural traps for the dentifrice. I

The only part of the brush that is apt ,to come into contact with the self-cleansing areas of the teeth are the long central bristles, but inasmuch ing with the longitudinal axis of the brush inflammation due to irritation at the root of the dental propillae. I

In Figure 10 the long bristles are shown going down between the teeth in and around the con-' tactpoints, dental embrasures and dental pro pillae. These long bristles have rounded heads. The shorter chisel points cannot enter these spaces.

In Figure 11 the brush is shown as having been moved horizontally; the long bristles having moved up on the dental embrasures and being in contact with the convex portions of the teeth.

In Figures 12 and 13 the brush is shown as tilted in order to bring'the crescent areas against the gingival third.

In. Figure 14 the palate is indicated at 44, the gum at 45, the lip at 46 and the tooth at 41.

When the brush is in the position shown in fulllines, the bevel surface 33 rides smoothly along the gum 45. If the brush is angularly turned toward the right it would either purposely or casually bring the chisel point 44 into position to dig into the gum 45, the convex head of long bristle 35 will encounter the gum firstand Will tend to move the chisel point 34 away from such gum. It will be appreciated that the improved brush acts for the preservation of health and prevention of diseases such as attack the teeth and adjacent tissues. This preservation and preven-v tion is accomplished by more efiicient and thorough cleaning of the non-self cleansing areas such as the gingival third of the teeth, gingival crevice, the dental embrasure and intradental and incisoral spaces.

In order to remove deposits from these spaces and massage the. gum with greatest .efliciency, the improved brush has been designed to fit the free margin of the gum, the oval shape of the teeth, the triangular shape of the embrasure which lies in between the teeth and the incisoral space to the contact between the teeth. To make. this possible the tufts of bristles are set in circu-' lar or oval to fit the gingival curve of the free of the bristles might have its major axis coincid-.

rather than transversely thereof.

In accordance with the form of the invention shown in the drawings, four circles of tufts are shown, but any desired number may be used, composed of eight tufts or any other suitable number.

The inverted arches 25 produce a cupped construction to produce contour fit on the teeth. The matched edges of the cup fit in the dental embrasure, incisoral and intradental spaces. The outer border of the cupped circle fits the gingival thirdrand the free margin of the gum.

Thus, the brush so designedfits the entire surfacev of the tooth both lingual and labial.

The matched border of the cups .0! projection face of the teeth makes it possible for the bristles.

tobe more'eve'nly distributed to the non-immune areas to facilitate cleaning of the gingival crevice head gum margin. In this connectionthe oval form,

Without laceration. By this fit, an even distribution of the bristles permits the pressure on the bristles to be evenly distributed and abrasion reduced to the minimum, thus protecting the enamel of the teeth. 7

The design may be constructed in a series of sizes. The diameter of the circles or ovals preferably equals the width of each of the anterior teeth and one-half of the width of the molars. By this design, in a series of sizes, any individual, regardless of age or size, can obtain a tooth brush to fit his dental apparatus (teeth and gums).

The oval or circular movement is recommended for the highest degree of efficiency in the cleansing process. Regardless of the movement used, the improved tooth brush fits all areas and insures a more thorough cleansing of all areas and surfaces than has heretofore been obtained. The equally distributed pressure makes possible a normal stimulation of the dental propillae or gum tissue in the inter-proximal space, gingival and freemargin of the gum. The free margin of the gum is protected by the lateral trim of the lateral borders of the lip of the cup in each circle. Otherwise stated the working point of the brush at each circle or oval is cusp-shaped.

The circles are preferably set in such relation that the ends of the tufts, contact or nearly contact'each other. The long lip of each cup'when placed side by side forms the incisoral space abrasure fit, while the short lip of the cup forms the gingival fit; the lateral or diagonal trim acting as a free margin protection against laceration and irritation of the gum free margin.

The width of the brush mouth piece increases or decreases in size to accommodate the size of the ovals or circles; while the length of the brush mouth piece increases or decreases to accommodate the number of circles or oval groups.

For convenience in description and understanding the lateral trim has been referred to certain diagonal planes but it is not essential that the trim be made along any particular angular lines; and the planes will preferably progressively change from the low points of the arches toward the high points because of the fact that bristle ends are tubularly arranged and therefore reoede in opposite directions towards the high points from a diagonal plane at the low point. Therefore the diagonal plane of trim or cleavage would have to move progressively towards the high points around the arcs of the circles or tubes, and this arrangement is desirable in order to give to the crescents a twisted or torsional shape to conform tothe similar shape of the gingival third.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims:

What is claimed is:

1. An improved tooth brush comprising a brush head having a working point, said working point comprising successive tufts of bristles disposed in units of tubular formation, the free ends of the tubular units being formed in substantially inverted arches, said free ends of said units also being beveled from the low portions of the inverted arches up toward, but short of, the high portions of the arches.

2. In an improved tooth brush having a head with a Working point, said working point corriprising tubularlyearranged groups of bristles, the free ends of said groups formed in an inverted arch with the high points of the inverted arch in substantially the middle of the brush head and the low point of the arch presented to the sides of the brush head, Said arched free ends of the tubularly arranged groups of bristles being intersected by a diagonal trim at the side of the brush head extending from a low side of the arch up to, but short of, the high points of the arch whereby toprovide beveled end surfaces and chisel edges for the intersected bristles, the nonintersected bristles at the high points of the arches being substantially arcuate.

3. In an improved tooth brush having a brush head with a working point, said working point comprising tubularly-arranged groups of tufts of bristles, said groups having hollow central portions, the free ends of the groups of bristles being inverted arch-shaped with the high points of the arch along substantially the center line of the brush head and .with the low points of the arch'presented to the side portions of the brush head, the long bristles at the central high points of the arch having rounded heads, the lateral bristles at opposite sides of the long central bristles having their free ends laterally trimmed along diagonal planes extending from the low points of the arch up to, but short of, the high points of the arch whereby to provide sharp chisel edges and bevel surfaces outwardly of said chisel edges.

4. In an improved tooth brush having a brush headwith a working point, said Working point comprising groups of tubularly-arranged tufts of bristles, said groups having hollow central portions, the free ends of the groups of bristles being inverted arch-shaped with the high points of the arch along substantially the center line of the brush head and with the low points of the arch presented to the side portions of the brush head, the long bristles at the central high points of the arch having rounded heads, the lateral bristles at opposite sides of the long central bristles having their free ends laterally trimmed along diagonal planes extending from the low points of the arch up to, but short of, the high points of the arch whereby to provide sharp chisel edges and bevel surfaces outwardly of said chisel edges, the upper projected ends of the diagonal planes intersecting above the working point of the brush, said diagonal planes in the brush head terminating short of the long central bristles, the free ends of the bristles between the upper ends of said diagonal planes and the heads of the long central bristles being cut at progressively smaller angles.

5. In an improved tooth brush having a head with a working point, said working point comprising tufts of bristles grouped tubularly, the free ends of the tubular groups being formed in an inverted arch, the space Within the tubularly arranged tufts being left free of bristles, the high points of the arch containing long bristles, the lateral bristles at the sides of said long bristles having bevel edges with chisel points, said bevel edges in the low points of the arch extending around arcuately toward the high points producing a substantially crescent shaped arced area corresponding substantially to the gingival third of a tooth.

GLENN L. CASTO. 

